Mom, 35, Found a Painless Lump While Breastfeeding But Her Mammogram Came Back Clear — It Was Triple-Negative Breast Cancer

She explained, “When you’re breastfeeding, you’re always checking to see what’s going on and if you have to pump or feed. When I saw it, I instantly knew it wasn’t a clogged milk duct. I’d had those before, and they were super painful.

“With this, there was absolutely no pain. It just appeared overnight.”

The discovery prompted her to contact her obstetrician-gynecologist (OB-GYN), because she felt it could be “serious,” even though she knew of no family history of the disease.

Two days after finding the lump, she saw her doctor on New Year’s Eve, who recommended a breast ultrasound — but she needed to get a mammogram first. After the mammogram showed no abnormalities, she underwent an ultrasound and was informed she needed a “rush order” for a breast biopsy.

After the biopsy, she was told she had breast cancer on January 8, 2025—and her doctor recommended genetic testing.

“I had no idea what receptors were. I thought you either had breast cancer or you didn’t,” she said. “I didn’t know there were types.”

She continued, ““Because I was young, healthy and had no other comorbidities, they encouraged me to get tested. At the time, I didn’t realize that there were other cancers connected to BRCA1 and BRCA2 inherited gene mutations.”

The most common breast cancer gene mutation, and the one doctors have known about the longest, is the BRCA gene mutation. The BRCA1 (BReast CAncer 1) or BRCA2 (BReast CAncer 2) genes help cells repair their DNA damage. Having a change, or mutation, in one of these genes increases a woman’s risk of getting breast cancer.

These gene mutations are commonly passed down in families; if a parent carries a BRCA gene mutation, there’s a 50-50 chance you could be carrying it as well.

In Krystina’s case, she had a BRCA1 gene mutation, which her family tested for and learned her father, brother, and sister also carried.

Genetic Testing for Breast Cancer: What is This Type of Test? And What Do My Results Mean?

Between 5% and 10% of breast cancer cases are thought to be hereditary. About 10% of patients who undergo genetic testing test positive for the BRCA1 or BRCA2 gene, Dr. Julie Rani Nangia, an assistant professor at Baylor College of Medicine, tells SurvivorNet.

“The genetic BRCA1 and (BRCA)2 mutations, if a woman has one of these mutations … it puts her at basically the highest quantifiable risk for getting breast cancer,” Dr. Port says. “We typically say between the 60 percent and 80 percent range. Having a BRCA1 and (BRCA)2 mutation also means that that person is at higher risk of getting breast cancer at an earlier age, and also maybe at risk for other cancers like ovarian cancer, like pancreatic cancer for men, prostate cancer and male breast cancer may be a concern.”

Since the discovery of the BRCA mutations in the 1990s, doctors have gone on to identify many other gene mutations that put people at a higher risk of developing breast cancer.

“There’s actually eight to 10 genes that also can put someone at a higher risk for breast cancer,” Dr. Port says, adding that usually that risk isn’t as high as the BRCA mutations. These additional gene mutations include PALB2, ATM, TP53, CHEK2, PTEN, CDH1 and STK11.

RELATED: Should I Get Genetic Testing to Assess My Risk for Breast Cancer?

“We call them more moderate penetrance genes and those genes, the risk of breast cancer associated with them can be anywhere from say 20 percent to 50 percent. So still very high, but lower than the BRCA genes that were the ones we originally described.”

Krystina, who underwent 16 rounds of neoadjuvant chemotherapy, had a double mastectomy three weeks after finishing treatment, followed by a year on a PARP inhibitor — and admitted she felt out of place during treatment, as she was “the only young woman in the entire [imaging] center.”

“Even when I got chemo, I never saw a young woman. And now I’m in multiple group chats with survivors across the country who are under 40,” Krysten, who also chose to undergo a hysterectomy to reduce her risk of ovarian cancer, told Susan G. Komen.

She ultimately found a community through Susan G. Komen and hopes sharing her story will encourage others to see a doctor when they notice concerning symptoms and remind them that they’re not alone.

Treating Triple Negative Breast Cancer

Understanding Triple-Negative Breast Cancer

Triple-negative breast cancer is one of the most aggressive forms of the disease and makes up approximately 20 percent of all breast cancers. Treatment varies from patient to patient and may include a combination of different treatments.

Early-stage triple-negative breast cancer (TNBC) treatments may use a combination of chemotherapy drugs.

Understanding Triple Negative Breast Cancer

For example, a CMF regimen combines the chemotherapy drugs cyclophosphamide, methotrexate, and fluorouracil. AC stands for doxorubicin (Adriamycin) with cyclophosphamide, and ACT indicates that a taxane drug is added to the regimen. Likewise, TC is a regimen of Taxotere and cyclophosphamide.

RELATED: In Triple Negative Breast Cancer, Drug Trodelvy Extends Life

Pembrolizumab and Early-Stage TNBC

In 2021, the FDA approved the immunotherapy drug pembrolizumab (Keytruda) to treat early-stage triple-negative breast cancer, based on the KEYNOTE-522 trial. Pembrolizumab was already used to treat other cancers, including melanoma and non-small cell lung cancer. Doctors heralded the FDA’s approval as a potentially paradigm-shifting advancement in breast cancer treatment.

For patients with stage 2 or 3 TNBC, adding pembrolizumab to combination chemotherapy before surgery increases the chances of living free of breast cancer, oncologist Dr. Sylvia Adams, director of the Breast Cancer Center at NYU Langone’s Perlmutter Cancer Center, has explained to SurvivorNet.

She was one of several researchers involved with the pembrolizumab trials. “It changes the standard of care and should be discussed with all patients diagnosed with stage 2-3 TNBC,” she said. “Yes, it’s a game-changer, though there is much more to be learned.”

Immunotherapy for Metastatic TNBC: An Updated Picture

Earlier reporting on this topic pointed to the IMpassion130 trial, which in 2019 led to accelerated FDA approval of atezolizumab (Tecentriq) plus nab-paclitaxel for PD-L1-positive metastatic triple-negative breast cancer — the first immunotherapy combination approved for this disease. However, that approval is no longer in effect.

The First Immunotherapy Approved For Breast Cancer Hope For Triple Negative Breast Cancer

The confirmatory trial, IMpassion131, failed to show a progression-free survival benefit when atezolizumab was added to paclitaxel, in either the PD-L1-positive population or the overall study population. Following an FDA review, the drug’s manufacturer voluntarily withdrew the accelerated approval for this indication in August 2021. The withdrawal was not attributed to any new safety concerns, but rather to the confirmatory trial not replicating the original results.

Instead, pembrolizumab plus chemotherapy is now the standard of care for patients with previously untreated metastatic TNBC whose tumors have a PD-L1 combined positive score of 10 or higher, since it has been shown to improve overall survival compared with chemotherapy alone.

Dr. Adams’ broader point about biomarkers still holds. She explained, “The question now becomes, is it only triple negative breast cancer that can benefit from immunotherapy, or are there other subtypes as well?

“If a tumor has the PD-L1 protein in it, that means there’s already an inflammatory response, that the patient’s immune system already recognized the tumor and was starting to work against it. The benefit of identifying such a strong biomarker in the triple negative subset will allow us to actually test for the presence and responsiveness to immunotherapy in other subtypes of breast cancer.”

Is Your Cancer Really Triple-Negative?

Dr. Heather McArthur, Clinical Director of the Breast Cancer Program at Simmons Cancer Center at UT Southwestern Medical Center, previously spoke with SurvivorNet about this topic.

You might be told you have triple-negative breast cancer, meaning your cancer is not being fueled by any of the three main receptors: estrogen, progesterone, or the HER2 protein. But you could now also be categorized as HER2-low rather than simply HER2-negative.

RELATED: What to Know About CDK4/6 Inhibitors as Breast Cancer Treatment: Weighing the Risks vs. Benefits

Breast cancer cells with higher-than-normal levels of HER2 are called HER2-positive; those with low levels of HER2 were traditionally called HER2-negative.

More recently, researchers have expanded this definition to include patients with minimal HER2 expression who do not meet the classic criteria for HER2-positive tumors. This group is called HER2 “low” and represents close to half of all breast cancer patients.

This distinction matters because HER2-low breast cancers are targetable with the FDA-approved drug Enhertu (fam-trastuzumab deruxtecan-nxki). Enhertu has shown strong effectiveness for appropriate patients and can meaningfully improve quality of life and survival.

It is therefore worth discussing your HER2 status—including whether you fall into the HER2-low category—with your doctor.

Treatment for Early-Stage Triple Negative Breast Cancer

When to Screen for Breast Cancer

Guidance on mammograms varies slightly by organization, which can confuse patients, but we’re here to help.

In April 2024, the U.S. Preventive Services Task Force (USPSTF) updated its recommendation, advising all women at average risk to get a mammogram every other year starting at age 40 and continuing through age 74 — a change from its 2016 guidance, which set the starting age at 50.

The USPSTF said moving the starting age to 40 could save roughly 19% more lives, and noted that Black women face a 40% higher breast cancer mortality risk than white women, a disparity the earlier guidelines didn’t address.

The American Cancer Society’s guidance is close but not identical: annual mammograms starting at 45, moving to every other year (or annual, if preferred) starting at 55.

Women with a strong family history of breast cancer, a BRCA mutation, chest radiation before age 30, early menstruation (before 12), or dense breast tissue are considered higher risk and may need to start screening earlier—however, that conversation should happen with a doctor rather than by following a general guideline.

Questions To Ask Your Doctor

If you have a breast cancer screening coming up or have recently had one, you may have questions you want answered. SurvivorNet’s proprietary AI tool “My Health Questions” is designed specifically for patients and caregivers, helping you prepare for conversations with your doctor and get clear, personalized guidance.

WATCH: How One Cancer Survivor and Her Sister Used ‘My Health Questions’ to Navigate Care

This powerful resource is embedded across the SurvivorNet website and delivers structured responses grounded in clinical guidelines and medically reviewed research, helping people better understand their treatment options and feel more confident navigating care.

My Health Questions can also help patients prepare useful questions ahead of their next appointment.

Contributing: SurvivorNet Staff

Learn more about SurvivorNet's rigorous medical review process.

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